On December 24, 1850, Robert and Clara Schumann received a sole visitor at their home in Düsseldorf—their friend Josef Wasielewski, the violinist, concertmaster, and later Robert's first biographer. Wasielewski was evidently the recipient on that occasion of a copy of their Rückert songs, Zwölf Lieder aus F. Rückerts Liebesfrühling, for the music is inscribed: “In commemoration of Christmas Eve, 1850, from Robert and Clara Schumann.” It was Clara's personal copy of the songs, on which Robert had written “for my Clara” when he had presented it to her on her birthday, September 13, 1841. For the three friends, the songs would have been a memento of their Leipzig days. Perhaps, too, the Schumanns spoke of the cycle's great personal significance and proudly showed their guest the verse letter Rückert had written to them; Wasielewski included it in an explanatory footnote to his list of Lieder composed in 1841.

The Zwölf Lieder—nine by Robert and three by Clara—constitute the only true compositional collaboration between the famous pair (discounting compositions by one of them based on a theme borrowed from the other). The songs bear a unique double opus number—op. 37/12—the first Robert’s, the second Clara’s. Based on poems by Friedrich Rückert (the poems and their translations appear in appendix 13.1), arguably Robert's favorite poet, the songs range from plain and luxurious strophic settings to simple and complex through-composed forms and consist of solos and duets. Clara's songs share the characteristics of Robert's style. The original edition was issued without identifying the composer of the individual songs. Contemporaries could not distinguish the composers, and even today listeners can be confounded. All in all, the songs are fine specimens that are inappropriately neglected. Hearing them is like walking through a gallery of unfamiliar paintings by famous artists.

Despite the unique circumstances of the group's origin and the attendant interest one would expect, these songs are seldom performed as a unit by the requisite two singers. The songs are treated unsympathetically by commentators, in part, I think, because the nature of the group is inadequately appreciated. Because Robert and Clara's collaboration is poorly understood, unwarranted and erroneous speculation about the compositional process has arisen.